Newbie question... My speakers specify an impedance, which does not match the impedance specified on the back of my amplifier. I have not perceived this as a problem, but am curious as to what this actually means. A low impedance (In very general terms=low resistance) means the speaker is 'tougher' for the amplifier to power, and vice versa? Thus, a lower impedance on the back of my amp than the impedance of the speakers means that the amp can supply more power than strictly required for the speaker...? And if so, a higher impedance on the amp means it probably may not match the speakers well? And finally, is it very important to match the impedance specified on the amp to that of the speakers, or is it only important to have a higher impedance on the speakers than on the amp?